1. Field of the Invention
This invention relates to a warning device for a friction pad or lining for use in a disk brake, and more particularly to a warning device which is best suited for use in a disk brake equipped with a ventilated disk.
2. Description of the Prior Art
Excessive wear of a friction pad or lining to be forced against a brake disk in an automotive disk brake leads to an accident and is a critical problem from viewpoint of safety of an automobile. For this reason, there have been proposed many attempts for warning the driver of wear of a friction pad or lining. However, prior art warning devices in general are resorted to an electric circuit to give a warning, resulting in a complicated construction and a tendency to cause various kinds of troubles.